// 数组
function testArr() {
  let list: number[] = [1, 23, 4];
  let ro1: Array<number> = [1, 2, 34, 5];
  let ro: ReadonlyArray<number> = [1, 2, 3, 4];
  interface ArrObj {
    name: string;
    age: number;
  }
  let list2: ArrObj[] = [{ name: "1234", age: 1234 }];
  let obj: ArrObj = {
    name: "1234",
    age: 1234,
  };
  return null;
}
// testArr()

// 元组 tuple
type x = [string, number];
let x:x = ["124", 1234];

// null 、undefined 、 void 、 never 整理

export {};
